ED_000552B_00067789_0_6ac47973-be99-4caf-80c0-0b3ad905708d

To: Spence, SandrafSpence. Sandra@epa.gov]

Cc: Wall, Dan[wall. dan@epa.gov]; Hermann, Karl[Hermann. Karl@epa.gov]; Pierce,

Maggie[Pierce. Maggie@epa.gov]; Laidlaw, Tina[Laidlaw. Tina@epa.gov]; McComb,
Martin[McComb. Martin@epa.gov]; Keteles, Kristen[Keteles. Kristen@epa.gov]

From: Myers, Craig

Sent: Wed 8/19/2015 12:47:12 AM

Subject: Re: Cement Creek/Animas Color

Please copy Kristin on this topic as well. Thx.

Sent from my iPhone

On Aug 18, 2015, at 5:44 PM, Spence, Sandra <Spence.Sandra@epa.gov> wrote:

Hi Craig,

Dan and I have spent a good portion of the day discussing and considering causes of the
green color you are seeing in the upper Animas/Cement creek. I suspected that you may be
seeing a shifting of valence states and iron chemistries in the system causing changes in
color. Generally, the reduced form of iron (Fe+2 as a sulfate) is bluish/green chalky in
solution. Aluminum forms a white precipitate that can appear chalky. Also, copper can
form sulfates/carbonates that appear bright blue/green. So, these metals could be involved.

I looked at the iron data collected in Cement Creek and Animas at two sites (I need to look
at more and will do that tomorrow). However, it appears that there are fluctuations
occurring between dissolved (likely reduced) iron and particulate (likely oxidized) iron and
there are times when the dissolved iron (blue/green in color) is significantly greater than the
particulate iron (orange in color). So, I believe it is quite feasible that the color you are
seeing is a result of iron/metals chemistry. More data analysis will occur tomorrow. The
sample/analysis we have planned will measure the oxidation state of iron; so, we can speak
more directly to this when we can get samples collected and data back.

We considered the possibility of a tracer study occurring in the watershed that is creating
the color. So, we’ve included a sample/analysis for fluorescein in our request. To determine
if the color is due to an algae bloom, we plan to measure chlorophyll a, which is a direct
algal indicator, as well as nutrient levels. So, that’s all I have for you right now.

Note the photo below and caption below it. This photo and caption are from a document
entitled, “Easter Pennsylvania Coalition for Abandoned Mine Reclamation.” Maybe the
color will look familiar to you - it’s due to iron/aluminum.

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Hope all is well and feel free to call me on my cell if you need more information,

-Sandie

Sandra Spence

Chief, Water Quality Unit

Ecosystems Protection Program

US EPA Region 8

1595 Wynkoop, Denver, CO

Mailcode 8-EPR-EP

Office 303-312-6947

Cell 303-870-7095/303-525-8041

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